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<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2014 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: AbstractFunction.html 842 2015-03-07 18:20:42Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.jsimpledb.parse.func;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import java.util.ArrayList;<a name="line.10"></a>
<span class="sourceLineNo">011</span><a name="line.11"></a>
<span class="sourceLineNo">012</span>import org.jsimpledb.parse.ParseContext;<a name="line.12"></a>
<span class="sourceLineNo">013</span>import org.jsimpledb.parse.ParseException;<a name="line.13"></a>
<span class="sourceLineNo">014</span>import org.jsimpledb.parse.ParseSession;<a name="line.14"></a>
<span class="sourceLineNo">015</span>import org.jsimpledb.parse.SpaceParser;<a name="line.15"></a>
<span class="sourceLineNo">016</span>import org.jsimpledb.parse.expr.ExprParser;<a name="line.16"></a>
<span class="sourceLineNo">017</span>import org.jsimpledb.parse.expr.Node;<a name="line.17"></a>
<span class="sourceLineNo">018</span>import org.jsimpledb.parse.expr.Value;<a name="line.18"></a>
<span class="sourceLineNo">019</span>import org.slf4j.Logger;<a name="line.19"></a>
<span class="sourceLineNo">020</span>import org.slf4j.LoggerFactory;<a name="line.20"></a>
<span class="sourceLineNo">021</span><a name="line.21"></a>
<span class="sourceLineNo">022</span>/**<a name="line.22"></a>
<span class="sourceLineNo">023</span> * Superclass of all {@link ParseSession} functions.<a name="line.23"></a>
<span class="sourceLineNo">024</span> *<a name="line.24"></a>
<span class="sourceLineNo">025</span> * @see Function<a name="line.25"></a>
<span class="sourceLineNo">026</span> */<a name="line.26"></a>
<span class="sourceLineNo">027</span>public abstract class AbstractFunction {<a name="line.27"></a>
<span class="sourceLineNo">028</span><a name="line.28"></a>
<span class="sourceLineNo">029</span>    protected final Logger log = LoggerFactory.getLogger(this.getClass());<a name="line.29"></a>
<span class="sourceLineNo">030</span>    protected final SpaceParser spaceParser = new SpaceParser();<a name="line.30"></a>
<span class="sourceLineNo">031</span>    protected final String name;<a name="line.31"></a>
<span class="sourceLineNo">032</span><a name="line.32"></a>
<span class="sourceLineNo">033</span>// Constructors<a name="line.33"></a>
<span class="sourceLineNo">034</span><a name="line.34"></a>
<span class="sourceLineNo">035</span>    /**<a name="line.35"></a>
<span class="sourceLineNo">036</span>     * Constructor.<a name="line.36"></a>
<span class="sourceLineNo">037</span>     *<a name="line.37"></a>
<span class="sourceLineNo">038</span>     * @param name function name<a name="line.38"></a>
<span class="sourceLineNo">039</span>     */<a name="line.39"></a>
<span class="sourceLineNo">040</span>    protected AbstractFunction(String name) {<a name="line.40"></a>
<span class="sourceLineNo">041</span>        if (name == null)<a name="line.41"></a>
<span class="sourceLineNo">042</span>            throw new IllegalArgumentException("null name");<a name="line.42"></a>
<span class="sourceLineNo">043</span>        this.name = name;<a name="line.43"></a>
<span class="sourceLineNo">044</span>    }<a name="line.44"></a>
<span class="sourceLineNo">045</span><a name="line.45"></a>
<span class="sourceLineNo">046</span>// Accessors<a name="line.46"></a>
<span class="sourceLineNo">047</span><a name="line.47"></a>
<span class="sourceLineNo">048</span>    /**<a name="line.48"></a>
<span class="sourceLineNo">049</span>     * Get the name of this function.<a name="line.49"></a>
<span class="sourceLineNo">050</span>     *<a name="line.50"></a>
<span class="sourceLineNo">051</span>     * @return function name<a name="line.51"></a>
<span class="sourceLineNo">052</span>     */<a name="line.52"></a>
<span class="sourceLineNo">053</span>    public String getName() {<a name="line.53"></a>
<span class="sourceLineNo">054</span>        return this.name;<a name="line.54"></a>
<span class="sourceLineNo">055</span>    }<a name="line.55"></a>
<span class="sourceLineNo">056</span><a name="line.56"></a>
<span class="sourceLineNo">057</span>    /**<a name="line.57"></a>
<span class="sourceLineNo">058</span>     * Get function usage string. For example: {@code pow(base, exponent)}.<a name="line.58"></a>
<span class="sourceLineNo">059</span>     *<a name="line.59"></a>
<span class="sourceLineNo">060</span>     * @return function usage string<a name="line.60"></a>
<span class="sourceLineNo">061</span>     */<a name="line.61"></a>
<span class="sourceLineNo">062</span>    public abstract String getUsage();<a name="line.62"></a>
<span class="sourceLineNo">063</span><a name="line.63"></a>
<span class="sourceLineNo">064</span>    /**<a name="line.64"></a>
<span class="sourceLineNo">065</span>     * Get summarized help (typically a single line).<a name="line.65"></a>
<span class="sourceLineNo">066</span>     *<a name="line.66"></a>
<span class="sourceLineNo">067</span>     * @return one line summarized description of this function<a name="line.67"></a>
<span class="sourceLineNo">068</span>     */<a name="line.68"></a>
<span class="sourceLineNo">069</span>    public abstract String getHelpSummary();<a name="line.69"></a>
<span class="sourceLineNo">070</span><a name="line.70"></a>
<span class="sourceLineNo">071</span>    /**<a name="line.71"></a>
<span class="sourceLineNo">072</span>     * Get expanded help (typically multiple lines). May refer to the {@linkplain #getUsage usage string}.<a name="line.72"></a>
<span class="sourceLineNo">073</span>     *<a name="line.73"></a>
<span class="sourceLineNo">074</span>     * &lt;p&gt;<a name="line.74"></a>
<span class="sourceLineNo">075</span>     * The implementation in {@link AbstractFunction} delegates to {@link #getHelpSummary getHelpSummary()}.<a name="line.75"></a>
<span class="sourceLineNo">076</span>     * &lt;/p&gt;<a name="line.76"></a>
<span class="sourceLineNo">077</span>     *<a name="line.77"></a>
<span class="sourceLineNo">078</span>     * @return detailed description of this function<a name="line.78"></a>
<span class="sourceLineNo">079</span>     */<a name="line.79"></a>
<span class="sourceLineNo">080</span>    public String getHelpDetail() {<a name="line.80"></a>
<span class="sourceLineNo">081</span>        return this.getHelpSummary();<a name="line.81"></a>
<span class="sourceLineNo">082</span>    }<a name="line.82"></a>
<span class="sourceLineNo">083</span><a name="line.83"></a>
<span class="sourceLineNo">084</span>// Parsing<a name="line.84"></a>
<span class="sourceLineNo">085</span><a name="line.85"></a>
<span class="sourceLineNo">086</span>    /**<a name="line.86"></a>
<span class="sourceLineNo">087</span>     * Parse function parameters.<a name="line.87"></a>
<span class="sourceLineNo">088</span>     *<a name="line.88"></a>
<span class="sourceLineNo">089</span>     * &lt;p&gt;<a name="line.89"></a>
<span class="sourceLineNo">090</span>     * The {@code ctx} will be pointing at the first parameter (if any) or closing parenthesis. This method should parse<a name="line.90"></a>
<span class="sourceLineNo">091</span>     * (but not evaluate) function parameters up through the closing parenthesis.<a name="line.91"></a>
<span class="sourceLineNo">092</span>     * &lt;/p&gt;<a name="line.92"></a>
<span class="sourceLineNo">093</span>     *<a name="line.93"></a>
<span class="sourceLineNo">094</span>     * @param session parse session<a name="line.94"></a>
<span class="sourceLineNo">095</span>     * @param ctx parse context<a name="line.95"></a>
<span class="sourceLineNo">096</span>     * @param complete false if parse is "for real", true if only for tab completion calculation<a name="line.96"></a>
<span class="sourceLineNo">097</span>     * @return parsed parameters object to be passed to {@link #apply apply()}<a name="line.97"></a>
<span class="sourceLineNo">098</span>     * @throws ParseException if parse fails, or if {@code complete} is true and there are valid completions<a name="line.98"></a>
<span class="sourceLineNo">099</span>     */<a name="line.99"></a>
<span class="sourceLineNo">100</span>    public abstract Object parseParams(ParseSession session, ParseContext ctx, boolean complete);<a name="line.100"></a>
<span class="sourceLineNo">101</span><a name="line.101"></a>
<span class="sourceLineNo">102</span>    /**<a name="line.102"></a>
<span class="sourceLineNo">103</span>     * Evaluate this function. There will be a transaction open.<a name="line.103"></a>
<span class="sourceLineNo">104</span>     *<a name="line.104"></a>
<span class="sourceLineNo">105</span>     * @param session parse session<a name="line.105"></a>
<span class="sourceLineNo">106</span>     * @param params parsed parameters returned by {@link #parseParams parseParams()}<a name="line.106"></a>
<span class="sourceLineNo">107</span>     * @return value returned by this function<a name="line.107"></a>
<span class="sourceLineNo">108</span>     * @throws RuntimeException if there is an error<a name="line.108"></a>
<span class="sourceLineNo">109</span>     */<a name="line.109"></a>
<span class="sourceLineNo">110</span>    public abstract Value apply(ParseSession session, Object params);<a name="line.110"></a>
<span class="sourceLineNo">111</span><a name="line.111"></a>
<span class="sourceLineNo">112</span>    /**<a name="line.112"></a>
<span class="sourceLineNo">113</span>     * Parse some number of Java expression function arguments. We assume we have parsed the opening parenthesis,<a name="line.113"></a>
<span class="sourceLineNo">114</span>     * zero or more previous arguments followed by commas, and optional whitespace. This will parse through<a name="line.114"></a>
<span class="sourceLineNo">115</span>     * the closing parenthesis.<a name="line.115"></a>
<span class="sourceLineNo">116</span>     *<a name="line.116"></a>
<span class="sourceLineNo">117</span>     * @param session parse session<a name="line.117"></a>
<span class="sourceLineNo">118</span>     * @param ctx parse context<a name="line.118"></a>
<span class="sourceLineNo">119</span>     * @param complete false if parse is "for real", true if only for tab completion calculation<a name="line.119"></a>
<span class="sourceLineNo">120</span>     * @param skippedArgs the number of arguments already parsed<a name="line.120"></a>
<span class="sourceLineNo">121</span>     * @param minArgs minimum number of arguments<a name="line.121"></a>
<span class="sourceLineNo">122</span>     * @param maxArgs maximum number of arguments<a name="line.122"></a>
<span class="sourceLineNo">123</span>     * @return parsed expressions<a name="line.123"></a>
<span class="sourceLineNo">124</span>     * @throws ParseException if parse fails, or if {@code complete} is true and there are valid completions<a name="line.124"></a>
<span class="sourceLineNo">125</span>     */<a name="line.125"></a>
<span class="sourceLineNo">126</span>    public Node[] parseExpressionParams(ParseSession session, ParseContext ctx, boolean complete,<a name="line.126"></a>
<span class="sourceLineNo">127</span>      int skippedArgs, int minArgs, int maxArgs) {<a name="line.127"></a>
<span class="sourceLineNo">128</span><a name="line.128"></a>
<span class="sourceLineNo">129</span>        // Parse parameters<a name="line.129"></a>
<span class="sourceLineNo">130</span>        final ArrayList&lt;Node&gt; params = new ArrayList&lt;Node&gt;(Math.min(maxArgs, minArgs * 2));<a name="line.130"></a>
<span class="sourceLineNo">131</span>        while (true) {<a name="line.131"></a>
<span class="sourceLineNo">132</span>            if (ctx.isEOF()) {<a name="line.132"></a>
<span class="sourceLineNo">133</span>                final ParseException e = new ParseException(ctx, "truncated input");<a name="line.133"></a>
<span class="sourceLineNo">134</span>                if (!params.isEmpty() &amp;&amp; params.size() &lt; minArgs)<a name="line.134"></a>
<span class="sourceLineNo">135</span>                    e.addCompletion(", ");<a name="line.135"></a>
<span class="sourceLineNo">136</span>                else if (params.size() &gt;= minArgs)<a name="line.136"></a>
<span class="sourceLineNo">137</span>                    e.addCompletion(")");<a name="line.137"></a>
<span class="sourceLineNo">138</span>                throw e;<a name="line.138"></a>
<span class="sourceLineNo">139</span>            }<a name="line.139"></a>
<span class="sourceLineNo">140</span>            if (ctx.tryLiteral(")")) {<a name="line.140"></a>
<span class="sourceLineNo">141</span>                if (params.size() &lt; minArgs) {<a name="line.141"></a>
<span class="sourceLineNo">142</span>                    throw new ParseException(ctx, "at least " + (skippedArgs + minArgs) + " argument(s) are required for function "<a name="line.142"></a>
<span class="sourceLineNo">143</span>                      + this.getName() + "()");<a name="line.143"></a>
<span class="sourceLineNo">144</span>                }<a name="line.144"></a>
<span class="sourceLineNo">145</span>                break;<a name="line.145"></a>
<span class="sourceLineNo">146</span>            }<a name="line.146"></a>
<span class="sourceLineNo">147</span>            if (params.size() &gt;= maxArgs) {<a name="line.147"></a>
<span class="sourceLineNo">148</span>                throw new ParseException(ctx, "at most " + (skippedArgs + maxArgs) + " argument(s) are allowed for function "<a name="line.148"></a>
<span class="sourceLineNo">149</span>                  + this.getName() + "()");<a name="line.149"></a>
<span class="sourceLineNo">150</span>            }<a name="line.150"></a>
<span class="sourceLineNo">151</span>            if (!params.isEmpty()) {<a name="line.151"></a>
<span class="sourceLineNo">152</span>                if (!ctx.tryLiteral(",")) {<a name="line.152"></a>
<span class="sourceLineNo">153</span>                    throw new ParseException(ctx, "expected `,' between " + this.getName() + "() function parameters")<a name="line.153"></a>
<span class="sourceLineNo">154</span>                      .addCompletion(", ");<a name="line.154"></a>
<span class="sourceLineNo">155</span>                }<a name="line.155"></a>
<span class="sourceLineNo">156</span>                this.spaceParser.parse(ctx, complete);<a name="line.156"></a>
<span class="sourceLineNo">157</span>            }<a name="line.157"></a>
<span class="sourceLineNo">158</span>            params.add(ExprParser.INSTANCE.parse(session, ctx, complete));<a name="line.158"></a>
<span class="sourceLineNo">159</span>            ctx.skipWhitespace();<a name="line.159"></a>
<span class="sourceLineNo">160</span>        }<a name="line.160"></a>
<span class="sourceLineNo">161</span><a name="line.161"></a>
<span class="sourceLineNo">162</span>        // Done<a name="line.162"></a>
<span class="sourceLineNo">163</span>        return params.toArray(new Node[params.size()]);<a name="line.163"></a>
<span class="sourceLineNo">164</span>    }<a name="line.164"></a>
<span class="sourceLineNo">165</span>}<a name="line.165"></a>
<span class="sourceLineNo">166</span><a name="line.166"></a>




























































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